We propose the formation of the Centers for Innovative Research to Control AIDS (CIRCA) as a clinical trials unit (CTU) devoted to the conduct of research proposed by the HIV Prevention Trials; Network (HPTN) and the Microbicide Trials Network (MTN). CIRCA will conduct these studies at five clinical research sites (CRS) located in New York City (NYC) and Newark, New Jersey-two of the communities most severely affected by the HIV epidemic in the US. CIRCA will focus on conducting studies with populations that are at the highest risk for HIV infection in the U.S. and that have traditionally been underrepresented in clinical trials including African Americans, Hispanics, women and substance users. CIRCA is a consortium administratively situated at the Mailman School of Public Health at Columbia University with five CRSs. The Harlem HIV Prevention Center and the University of Medicine & Dentistry of New Jersey (UMDNJ) site will participate in both HPTN and MTN studies, the two New York Blood Center sites will participate in HPTN studies and the Bronx-Lebanon Hospital Center site will participate in MTN studies. Tie four CRSs in NYC have worked together for the past five years successfully conducting HPTN sponsored prevention and Microbicide studies. They are partnering in this application with the UMDNJ site, a site with extensive experience in prevention and with a commitment to the same populations at risk for HIV. The CIRC^ investigators bring a wealth of expertise that spans the disciplines required to advance the scientific agendas of the HPTN and MTN. They have led and participated in multi-center research, have been key participants in scientific working groups and protocol teams, have practical field experience, have developed innovative behavioral and biomedical interventions and have utilized creative methods to evaluate the impact of the interventions. Most importantly, the investigators have gained the trust of their communities. They have established the framework for the ethical conduct of research in disenfranchised communities. They have formed a vigorous and vibrant community advisory board to ensure community education and involvement. CIRCA is a cohesive unit with an efficient organizational plan, effective recruitment and retention plans, a rigorous quality assurance system and a meticulous process for data collection and management. Unfortunately, the magnitude of the HIV epidemic in the US is underestimated. More than 40,000 new HIV infections occur every year, primarily in those very communities where CIRCA sites are situated. The complementary skills and experiences of the CIRCA staff and investigators as well as their shared commitment to their communities will enable them to contribute to the discovery of new strategies to prevent the further spread of HIV in the US and around the world. ADMINISTRATIVE COMPONENT: